The invention relates to improvements in portable muscle building and exercising apparatus, and more particularly to improvements in apparatus of the type wherein a resilient element is designed and mounted to store varying amounts of energy in the course of a muscle building and exercising operation.
Fitness centers and similar body building establishments are equipped with muscle building apparatus in the form of machines which can be set up to permit the user to carry out selected body building exercises, i.e., to exercise and strengthen selected muscles or groups of muscles. For example, a so-called armcurl extension machine is designed to exercise the muscles in the upper arms of the user. The user moves both arms to positions in which the machine offers a certain resistance to pull or traction, and the underarms are thereupon alternatively raised and lowered without altering the level of the hands. The machine comprises a weight and the level of such weight is indicative of the applied pull. Thus, in order to make sure that the level of the hands (and hence of the weight) remains unchanged, the user of the machine must continuously observe the weight while the underarms are caused to move up and down. One of the underarms is moved up while the other underarm is caused to move down, and vice versa. The thus generated pulling or traction moments are deflected by one or more pulleys or gears at a level above the weight. The just described machine is rather heavy and bulky so that it is not suitable for transport, e.g., to be taken along on trips. Moreover, the machine is expensive because it comprises a large number of rather complex and bulky parts (such as the aforementioned weight). The cost and bulk of the machine preclude its use in private homes or in apartments except if the owner of the dwelling can afford to set up a separate room for the sole purpose of accommodating the exercising machine. Still further, the machine is not sufficiently versatile, i.e., it can only be used for the exercising of certain muscles or certain groups of muscles. Additional machines must be used to exercise other muscles or groups of muscles which almost invariably limits the utilization of such machines to fitness centers and to other establishments which are normally remote from the home and, in most instances, can be used only upon payment of a fee or by belonging to a health club.
It was already proposed to employ portable muscle building apparatus which can be put to use to exercise selected muscles or groups of muscles and are, at least in part, more versatile than the aforedescribed specially designed machines A presently known portable exercising apparatus employs a housing for a spring which is adapted to be stressed to different degrees. The housing carries a device serving as a means for visually indicating the degree of stress upon the confined spring and as a means for indicating whether or not a selected stress upon the spring is maintained. The entire apparatus is sufficiently compact to be insertable into a pocket. A drawback of such portable apparatus is that the device which indicates the degree of stress as well as the duration of application of a particular stress is designed to generate optical signals, i.e., it is necessary to observe such device in order to ascertain the extent or degree of the applied stress. Continuous observation is necessary if the user of the portable apparatus wishes to ensure that the degree of stress remains unchanged or that it changes only within a selected narrow range. This limits the versatility of the apparatus or renders it less acceptable to certain users who are interested in performing the muscle building exercises under very specific circumstances, e.g., while the degree of stress which is applied to the spring varies very little or not at all. The spring is normally assembled of several rubber bands or strips, and the device which generates an optical signal when a desired degree of stress upon the spring has been reached includes a diode which lights up only when the applied stress reaches the selected value and only as long as the applied stress is not reduced below the selected value In other words, the user must look at the diode in order to ascertain the magnitude of stress upon the spring. An observation of the diode is not possible if the housing is located behind the back of the user, and such observation is equally impossible under numerous other circumstances of possible use of the just described portable exercising apparatus. A person who intends to exercise her or his muscles with the exertion of large or very large forces is particularly unlikely to be in a position or condition to continuously observe the diode rather than concentrating on the application of stresses to the spring.